Ashton is believed to be Andy Robinson's preferred choice

Baron says he rang the chief executives of Bath, Wasps and Saracens last week regarding speculation their coaches could join the England set-up.

Calleja claimed the uncertainty over Ashton is hampering Bath's planning.

"For Bob to say that they have not had an approach from us is a lie," Baron told The Guardian newspaper.

Interview: Bath director of rugby Jack Rowell

Baron said "by far the longest conversation" of the three he had with the chief executives was with Calleja, who he said was "aggressive".

"I explained to him how the recruitment process would progress, emphasising that the RFU wanted to be open and above board in all this," Baron added.

"He became very angry at the thought we might be approaching one of his coaching staff and that we would not be allowed to do so.

"His attitude was totally different to that of Saracens and Wasps, who both instantly gave us permission to talk to any of their staff we were interested in."

I'm sure Brian's heart would pull him that way, and Bath would support him Bath director of rugby Jack Rowell

Baron added: "We negotiated the release of Andy Robinson from his contract at Bath six years ago and we know what the process involves."

The deadline for applicants for the three England vacant assistant coach positions (defence, attack and forwards) is this Friday.

The RFU believes Ashton has a six-month release clause in his contract, which Calleja insists has three years to run, with no escape clause.

"While he is legally free to apply for the job, he would only be allowed to leave if the RFU bought him out of his contract," Calleja said.

Robinson is due to name his squad for next month's two-Test tour of Australia on Monday, and is keen to have his assistants in place as soon as possible.

Ford to discuss Saracens future

Saracens coach Mike Ford, a favourite for the England defence coach role after Wasps' Shaun Edwards ruled out a full-time role, is holding talks over his future at Sarries.

But Ford, Ireland's defence coach for four years, is also being courted by new Wales head coach Gareth Jenkins, who he worked alongside with the Lions midweek team last summer.

"It's flattering to be linked with both countries," Ford said. "I'd like to be with an international team again. I had a great time with Ireland and I miss working at the highest level."

Former Leicester coach John Wells, already on the RFU payroll with the National Academy, is believed to the front-runner for the forwards coach position.

Ironically, Bath director of rugby Jack Rowell, the former England coach, helped fuel the speculation over Ashton in a recent interview with BBC Radio Five Live.

"When you get the call from England, that's a big thing to say 'no' to," Rowell said.

"I'm sure Brian's heart would pull him that way, and Bath would support him if he decided to do that. If I were a betting man, I would think that could well happen."

While admitting it would be painful to find a new head coach, Ashton having only returned to Bath in January, Rowell said England "should take primacy of purpose".